Intravascular catheter having an expandable incising portion

ABSTRACT

An intravascular catheter device for treating atherosclerotic material located within a blood vessel includes an expandable portion is secured to a catheter tube having a centerline. The expandable portion includes a plurality of struts pivotably attached to the expandable portion for movement between a closed position where the struts extend parallel to the centerline and an opened position where the struts splay outwardly at an angle from the centerline. A sharpened edge associated with at least one of struts creates an incision in the atherosclerotic material when the expandable portion is placed in the opened position and retracted axially through the blood vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 14/990,883filed Jan. 8, 2016, which is a divisional of application Ser. No.13/613,914, filed Sep. 13, 2012, which claims the benefit of U.S.Provisional Application No. 61/534,018, filed Sep. 13, 2011, thedisclosures of each of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates in general to intravascular catheters, such ascan be used during minimally invasive surgical procedures. Inparticular, this invention relates to an intravascular catheter havingan expandable incising portion.

Atherosclerosis is a chronic condition in which atheromatous plaqueaccumulates on the inner walls of a blood vessel. As a result, the bloodvessel walls can become inflamed and, over time, may harden to formatherosclerotic lesions that cause a narrowing of the vessel lumen. Insevere cases, the atherosclerotic lesions can rupture and induce theformation of thrombus (i.e., blood clots), which can prevent blood flowthrough the narrowed vessel lumen.

There are known procedures and devices for treating or otherwisereducing the risks associated with atherosclerosis. For example, anangioplasty is a procedure in which a balloon catheter is inserted intoa narrowed region of the vessel lumen via a delivery catheter. Theballoon catheter includes a flexible tube having an inflatable balloonat an end thereof. Once positioned in the narrowed region, the balloonis inflated in order to dilate the narrowed vessel lumen. The pressurein the balloon is generally sufficient to compress the accumulatedplaque. However, in some cases it would be desirable to fragment theatherosclerotic lesions. Thus, it would be desirable to provide anintravascular catheter having an expandable portion that can beselectively controlled by a user and adapted to create incisions inatherosclerotic material to facilitate fragmentation of the materialduring an angioplasty procedure.

SUMMARY OF THE INVENTION

This invention relates to an intravascular catheter device for useduring a surgical procedure. The catheter device includes a cathetertube having an expandable portion with a plurality of struts eachdefining an outer surface. The expandable portion is operable between aclosed position, wherein the expandable portion has a first diameter,and an opened position, wherein the expandable portion has a seconddiameter that is larger than the first diameter. An incising element isprovided on the outer surface of at least one of the struts. Theincising element has a sharpened edge that extends outwardly in a radialdirection from the outer surface of the strut for creating an incisionin atherosclerotic material located within a blood vessel when theexpandable portion is in the opened position.

Various aspects of this invention will become apparent to those skilledin the art from the following detailed description of the preferredembodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a catheter device that includes a handleassembly and a catheter tube having an expandable incising portion, inaccordance with a first embodiment of this invention.

FIG. 2 is a cross-sectional side view of the handle assembly taken alongsection line 2-2 shown in FIG. 1 when the catheter device is in a firstoperating mode.

FIG. 3 is an enlarged cross-sectional side view of the catheter tubetaken along section line 3-3 shown in FIG. 1 illustrating the expandableincising portion disposed within a blood vessel.

FIG. 4 is a cross-sectional end view of the expandable incising portiontaken along section line 4-4 shown in FIG. 3.

FIG. 5 is a cross-sectional side view of the handle assembly taken alongsection line 2-2 shown in FIG. 1 when the catheter device is in a secondoperating mode.

FIG. 6 is an enlarged cross-sectional side view of the catheter tubetaken along section line 3-3 shown in FIG. 1 illustrating the expandableincising portion in an opened position.

FIG. 7 is a cross-sectional end view of the expandable incising portiontaken along section line 7-7 shown in FIG. 6.

FIG. 8 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a second embodiment of thisinvention.

FIG. 9 is a side view of the catheter tube shown in FIG. 8 illustratingthe expandable incising portion in an opened position.

FIG. 10 is a cross-sectional end view of the expandable incising portiontaken along section line 10-10 shown in FIG. 9.

FIG. 11 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a third embodiment of thisinvention.

FIG. 12 is a side view of the catheter tube shown in FIG. 11illustrating the expandable incising portion in an opened position.

FIG. 13 is an end view of the catheter tube as shown in FIG. 12.

FIG. 14 is an enlarged side view of a catheter tube having an expandableincising portion, in accordance with a fourth embodiment of thisinvention.

FIG. 15 is a side view of the catheter tube shown in FIG. 14illustrating the expandable incising portion in an opened position.

FIG. 16 is an end view of the catheter tube as shown in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, there is illustrated in FIG. 1 a catheterdevice, indicated generally at 10, in accordance with this invention.The illustrated catheter device 10 is configured to treat or reduce therisks associated with atherosclerosis. In general, the catheter device10 includes an expandable incising portion that can be inserted into ablood vessel and expanded to create incisions in atheroscleroticmaterial that has accumulated on inner walls of the blood vessel. Theincisions facilitate the fragmentation of the atherosclerotic materialduring a subsequent angioplasty or atherectomy procedure. Although thecatheter device 10 will be described and illustrated in the context oftreating atherosclerosis, it should be appreciated that the catheterdevice 10 can be used in any desired environment and for any desiredpurpose.

Referring now to FIGS. 1 and 2, the illustrated catheter device 10includes a handle assembly, indicated generally at 20. The illustratedhandle assembly 20 includes an elongated, cylindrical handle body 21.The handle body 21 may alternatively have any other shape that issuitable for easy handling by a surgeon. Further, the handle body 21 canbe made from any suitably rigid material including, but not limited to,stainless steel or polymers.

As shown in FIG. 2, the illustrated handle body 21 defines an internalchamber 22. A passage 23 extends into an end portion of the handle body21 for communication with the internal chamber 22. The handle body 21further includes a slot 24 that extends through a side wall thereof forcommunication with the internal chamber 22. The illustrated slot 24 mayhave any length or width as desired. As shown in FIG. 1, an indicator24A may be provided on the handle body 21 adjacent to the slot 24. Forexample, the indicator 24A can be a visual scale or any other indicatingmeans, the purpose of which will be explained below.

The illustrated handle assembly 20 also includes a control member 25that is supported on the handle body 21 for sliding movement within theslot 24. For example, the control member 25 is movable between a forwardposition (shown in FIG. 2), a rearward position (shown in FIG. 5), orany position therebetween, which will be further explained below. Asshown in FIG. 2, the illustrated control member 25 includes a baseportion 26 that is disposed within the internal chamber 22 of the handlebody 21. The base portion 26 may define an outer cross-sectional shapethat generally corresponds with a cross-sectional shape of the internalchamber 22, although such is not required. Alternatively (or inaddition), the control member 25 may be movably supported on the handlebody 21 by a bearing, a bushing, a guide rail, or any other structuralmeans. In other embodiments, the control member 25 may be supported forrotational movement, pivotal movement, or any other type of movementrelative to the handle body 21, the purpose of which will becomeapparent below. The visual indicator 24A, described above, is configuredto identify the relative position of the control member 25 with respectto the handle body 21.

The illustrated handle assembly 20 also includes a locking mechanism 27that is configured to temporarily secure the control member 25 in adesired position, although such is not required. As shown in FIG. 2, theillustrated locking mechanism 27 includes a plurality of protrusionsthat are spaced apart from one another along an inner surface of theslot 24. The control member 25 frictionally engages the protrusions tohold the control member 25 in the desired position. Alternatively, thelocking mechanism 27 may be a threaded fastener, a pivotal latch, apush-button release, or any other mechanism that is configured to securethe control member 25 in a desired position.

Referring now to FIGS. 1 through 3, the illustrated catheter device 10also includes a catheter tube 30 that extends from the handle assembly20. The catheter tube 30 is an elongated, flexible member having aproximal end that is secured to the handle assembly 20 and a distal endthat extends therefrom. The catheter tube 30 can be made from anybiocompatible material including, but not limited to, polyvinyl,polyethylene, nitinol, or stainless steel. Further, the catheter tube 30can have any outer diameter, length, or wall thickness.

As shown in FIG. 2, the proximal end of the catheter tube 30 is securedto the handle body 21 and communicates with the internal cavity 22through the passage 23. The catheter tube 30 may be secured to thehandle body 21 using a flanged connection, a fused connection, anadhesive, a press-fit connection, a threaded connection, or any othersecuring means. Alternatively, the catheter tube 30 may be secured tothe handle body 21 using a connector or any other type of attachmentdevice.

As shown in FIGS. 1 and 3, an expandable portion 32 is provided on thedistal end of the catheter tube 30. The illustrated expandable portion32 is a cylindrical member having a longitudinal axis. The expandableportion 32 can be made from a generally resilient material that is ableto flex between various positions, such as polyvinyl, polyethylene,nitinol, or stainless steel. The expandable portion 32 can be secured tothe catheter tube 30 in any manner including, but not limited to, afused connection, an adhesive, a press-fit connection, a threadedconnection, or any other securing means. Alternatively, the expandableportion 32 can be integrally formed from the catheter tube 30. Further,the expandable portion 32 can have any outer diameter, length, or wallthickness.

The illustrated expandable portion 32 has a pair of struts 34A and 34B.The illustrated struts 34A and 34B are separated by a pair oflongitudinally extending slits 35A and 35B that extend through sidewalls of the expandable portion 32. As shown in FIG. 4, the slits 35Aand 35B are equally spaced apart from one another around thecircumference of the expandable portion 32 such that the struts 34A and34B have the same circumferential widths, although such is not required.The struts 34A and 34B may have any length, circumferential width, orcross-sectional shape as desired.

As shown in FIGS. 3 and 4, the illustrated expandable portion 32 alsoincludes a pair of incising elements 36 that are respectively providedalong outer surfaces of the struts 34A and 34B. The incising elements 36can be atherotomes or other incising members having arcuate shapededges, for example, that are configured to create incisions inatherosclerotic material as will be explained below. The illustratedincising elements 36 extend parallel with the longitudinal axis of theexpandable portion 32 and outwardly in a radial direction therefrom. Theincising elements 36 are equally spaced apart from one another aroundthe circumference of the expandable portion 32. The expandable portion32 may, however, have any number or configuration of incising elements36 provided around the circumference thereof. Further, the incisingelements 36 can have any cross-sectional shape, longitudinal length, orheight and can be made from any suitable material including, but notlimited to, tempered steel, stainless steel, high carbon steel, orceramics. The incising elements 36 can be molded with the struts 34A and34B or may otherwise be secured thereto in any manner such as, forexample, using a welded or soldered connection, an adhesive, or anyother fastening means.

The distal end of the expandable portion 32 may optionally include a tipmember 38. The illustrated tip member 38 has a generally conical shapethat facilitates insertion of the catheter tube 30 within a blood vessel50 (see FIGS. 3 and 4) and subsequent travel therethrough. The tipmember 38 may, however, have any desired shape. An aperture may axiallyextend through the tip member 38, the purpose of which will be explainedbelow. The tip member 38 can be integrally formed with the expandableportion 32 or may be secured thereto, such as with an adhesive or thelike. Further, the tip member 38 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, stainless steel, or polyether block amide.

As shown in FIGS. 2 through 4, the illustrated catheter device 10 alsoincludes an inner sleeve 40, although such is not required. The innersleeve 40 is a flexible, tubular member that is supported for slidingmovement within the catheter tube 30, the purpose of which will beexplained below. The inner sleeve 40 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, stainless steel, or a woven material. Further, the inner sleeve40 can have any outer diameter, length, or wall thickness. The innersleeve 40 need not be a tubular member but may alternatively be a solidwire, a braided wire, or the like.

As shown in FIG. 2, a proximal end of the inner sleeve 40 extends fromthe catheter tube 30 and into the internal chamber 22 of the handle body21. The proximal end of the inner sleeve 40 is secured to the baseportion 26 of the control member 25 for sliding movement therewith, thepurpose of which will be explained below. The inner sleeve 40 can besecured to the base portion 26 by a flanged connection, a fusedconnection, an adhesive, a threaded connection, or any other securingmeans.

As shown in FIG. 3, the inner sleeve 40 extends through an entire lengthof the catheter tube 30. A distal end of the inner sleeve 40 that isopposite the handle assembly 20 is secured to the tip member 38, whichis in turn secured to the expandable portion 32. The inner sleeve 40 maybe secured to the tip member 38 in any manner including, but not limitedto, a fused connection, an adhesive, a fastener, or the like.

Referring back to FIGS. 1 and 2, the illustrated catheter device 10 alsoincludes a protective sheath 42 that is supported for sliding movementalong an outer surface of the catheter tube 30, although such is notrequired. The protective sheath 42 can be made from any biocompatiblematerial including, but not limited to, polyvinyl, polyethylene,nitinol, or stainless steel. Further, the protective sheath 42 can haveany outer diameter, length, or wall thickness. The purpose of theprotective sheath 42 will be explained below.

The illustrated protective sheath 42 includes a flange 44 thatfacilitates sliding movement of the protective sheath 42 relative to thecatheter tube 30. The illustrated flange 44 is an annular member that islocated at an end of the protective sheath 42 nearest the handleassembly 20. The flange 44 can be integrally formed with the protectivesheath 42 or may otherwise be secured thereto in any manner, such aswith an adhesive or the like. It should be appreciated that the flange44 can have any shape or may alternatively be configured in any mannerto accomplish the functions described herein and below.

The operation of the catheter device 10 will now be described withreference to FIGS. 1 through 7. Referring initially to FIGS. 1 through4, the catheter device 10 is illustrated in a first operating mode. Inthe first operating mode, the control member 25 on the handle assembly20 is located in the forward position relative to the handle body 21.The inner sleeve 40 fully extends into the catheter tube 30 such thatthe expandable portion 32 is in a closed position, as shown in FIGS. 3and 4. In the closed position, the struts 34A and 34B are generallyparallel with one another and with the inner sleeve 40. The slits 35Aand 35B (illustrated by the dashed lines in FIG. 3) remain in agenerally closed configuration. As such, the expandable portion 32defines an initial diameter D1, which is generally the same diameter asthe remaining length of the catheter tube 30. The initial diameter D1 ofthe expandable portion 32 may, however, be any desired dimension.

When the catheter device 10 is in the first operating mode, the distalend of the catheter tube 30 can be percutaneously inserted into a bloodvessel 50, as shown in FIGS. 3 and 4. The illustrated catheter tube 30is then advanced through the blood vessel 50 along a guide wire 52,which extends through the catheter device 10. For example, the guidewire 52 may fully extend through the inner sleeve 40, into the internalchamber 22 of the handle body 21, and exit a rear end of the handleassembly 20 (see FIG. 2). The catheter tube 30 is advanced along theguide wire 52 until the expandable portion 32 is positioned in anarrowed region of the blood vessel 50 caused by atheroscleroticmaterial 54. Alternatively, the catheter tube 30 can be inserted intothe blood vessel 50 and guided therethrough by a delivery catheter (notshown) or any other suitable procedure. During insertion and advancementof the catheter tube 30 through the blood vessel 50, the optionalprotective sheath 42 is preferably positioned over the expandableportion 32, thereby preventing the incising elements 36 from coming intocontact with inner walls of the blood vessel 50.

Once the expandable portion 32 is positioned in the narrowed region ofthe blood vessel 50, the incising elements 36 can be exposed by slidingthe protective sheath 42 back from the distal end of the catheter tube30, as indicated by the direction arrows in FIG. 3. The illustratedprotective sheath 42 can be moved in this manner by pulling the flange44 towards the handle assembly 20, which is indicated by the directionarrows in FIG. 2.

Referring now to FIGS. 5 through 7, the catheter device 10 isillustrated in a second operating mode. To achieve the second operatingmode, the control member 25 is moved from the forward position to therearward position, as indicated by the direction arrow in FIG. 5. As thecontrol member 25 is moved to the rearward position, the inner sleeve 40is drawn within the catheter tube 30 thereby reducing the relativelength of the inner sleeve 40 with respect to the catheter tube 30. Thedistal end of the inner sleeve 40 is attached to the tip member 38, asdescribed above, causing the expandable portion 32 to become axiallycompressed between the tip member 38 and the distal end of the cathetertube 30. As a result, the struts 34A and 34B bow or expand outwardly ina generally arcuate fashion thereby defining an opened position. In theopened position, the expandable portion 32 defines a second diameter D2that is larger than the initial diameter D1 when the expandable portion32 is in the closed position. As shown in FIG. 6, the incising elements36 are respectively positioned along the radially outer most surfaces ofthe struts 34A and 34B. Further, the outer most surfaces of the struts34A and 34B may define a generally flat portion along a length thereofin the opened position, the purpose of which will be explained below,although such is not required. It should be appreciated that the struts34A and 34B can have any lengths such that the expandable portion 32 canachieve a desired overall second diameter D2 in the opened position.

During operation of the catheter device 10, the second diameter D2 canbe increased or decreased by selective movement of the control member 25between the forward and rearward positions. For example, a larger seconddiameter D2 can be achieved by moving the control member 25 furthertowards the rearward position. Conversely, a smaller second diameter D2can be achieved by moving the control member 25 further towards theforward position. The visual indicator 24A can be used to identify theinstantaneous second diameter D2 of the expandable portion 32.Alternatively (or in addition), the struts 34A and 34B may be biased inthe opened position so as to automatically expand outwardly to thesecond diameter D2 when the protective sheath 42 is slid back from theexpandable portion 32. As such, sliding movement of the protectivesheath 42 relative to the struts 34A and 34B can be used to selectivelycontrol the second diameter D2. In this configuration, the inner sleeve40 and the movable components of the handle assembly 20 may not benecessary.

When the catheter device 10 is in the second operating mode, theexpandable portion 32 can be pulled along the guide wire 52 through thenarrowed region of the blood vessel 50. This can be accomplished bypulling on the handle assembly 20. In doing so, the incising elements 36engage the atherosclerotic material 54 and create longitudinal incisions56 therein. As shown in FIGS. 6 and 7, the outer surface area of thearcuate shaped struts 34A and 34B, which is adjacent to the incisingelement 36, is configured to ride along a surface of the atheroscleroticmaterial 54, thereby limiting the depth of the incisions 56 andpreventing the incising members 36 from cutting the walls of the bloodvessel 50. The expandable portion 32 can be moved any distance along theguide wire 52 to create incisions 56 having any desired length. Afterthe incisions 56 are made in the atherosclerotic material 54, thecatheter device 10 can be returned to the first operating mode (shown inFIGS. 1 through 4) by moving the control member 25 to the forwardposition. In doing so, the expandable portion 32 returns to the closedposition. The protective sheath 42 can be slid over the expandableportion 32 and the catheter tube 30 may be removed from the blood vessel50.

Alternatively, the catheter device 10 can be used to create additionalincisions 56 in the atherosclerotic material 54. For example, after thecatheter device 10 has been returned to the first operating mode, theexpandable portion 32 can be relocated within the narrowed region of theblood vessel 50. The catheter tube 30 can then be rotated within theblood vessel 50 by rotating the handle assembly 20 so as to align theincising elements 36 with other portions of the atherosclerotic material54. The previous steps can then be repeated any number of times to makemultiple passes through the narrowed region of the blood vessel 50 andcreate additional incisions in the atherosclerotic material 54.

Thus, it should be appreciated that the illustrated catheter device 10is advantageous in many respects. In one example, the second diameter D2of the expandable portion 32 can be selectively controlled by operationof the handle assembly 20 or by sliding movement of the protectivesheath 42. This enables the catheter device 10 to be adapted for use inblood vessels 50 of different sizes or varying diameters. In anotherexample, the illustrated catheter device 10 can apply varying magnitudesof radial forces to the atherosclerotic material 54 by controlling theamount of force being applied to the control member 25 on the handleassembly 20. This enables the catheter device 10 to generate sufficientradial force to create incisions 56 in atherosclerotic material 54 whilereducing the potential for tearing the walls of the blood vessel 50. Inyet another example, the catheter device 10 can be used to make anynumber of passes during a single procedure to make multiple incisions 56in atherosclerotic material 54 of varying lengths and shapes.

Referring now to FIGS. 8 through 10, there is illustrated a cathetertube 130 having an expandable portion 132, in accordance with a secondembodiment of this invention. The catheter tube 130 and the expandableportion 132 may include any structural features as described andillustrated above in the previous embodiment, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 100 (i.e., 110, 120, 130, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 130 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 132 is provided on a distal end of the catheter tube 130 and mayinclude a tip member 138. The catheter tube 130 may also include aninner sleeve 140 and a protective sheath (not shown), which is alsodescribed above in the first embodiment.

In the illustrated embodiment, however, the expandable portion 132includes four struts 134A, 1348, 134C, and 134D that are respectivelyseparated by four longitudinally extending slits 135A, 135B, 135C, and135D. The illustrated struts 134A, 134B, 134C, and 134D each include anincising element 136, although such is not required. It should beappreciated that the expandable portion 132 may have any number orconfiguration of struts and incising elements as desired.

As shown in FIG. 8, the illustrated expandable portion 132 furtherincludes recessed portions 160 that respectively extend into the outersurfaces of the struts 134A, 134B, 134C, and 134D. For example, thestruts 134A, 134B, 134C, and 134D can be slightly bowed inwardly towardthe inner sleeve 140 when in the closed position or, alternatively, mayhave a reduced thickness along a central portion thereof to create therecessed portions 160. The illustrated incising elements 136 arerespectively disposed within the recessed portions 160. Thus, when thecatheter tube 130 is inserted into a blood vessel, as described above,the recessed portions 160 help to prevent the incising elements 136 fromcoming into contact with inner walls of the blood vessel. On the otherhand, when the expandable portion 132 is expanded to an opened position,as explained below, the incising elements 136 become exposed from therecessed portions 160. It should be appreciated that the recessedportions 160 can eliminate or reduce the need for the protective sheath(not shown). The guide wire 152 may extend through the entire device.

The expandable portion 132 can be operated between a closed position(shown in FIG. 8) and an opened position (shown in FIGS. 9 and 10) byselective movement of the inner sleeve 140 relative to the catheter tube130, as described above in the first embodiment. Alternatively (or inaddition), the struts 134A, 1348, 134C, and 134D can be biased in theopened position. In such an embodiment, the protective sheath (notshown) can be used to effect movement of the expandable portion 132between the closed position and the opened position.

Referring now to FIGS. 11 through 13, there is illustrated a cathetertube 230 having an expandable portion 232, in accordance with a thirdembodiment of this invention. The catheter tube 230 and the expandableportion 232 may include any structural features as described andillustrated above in the previous embodiments, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 200 (i.e., 210, 220, 230, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 230 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 232 is provided on a distal end of the catheter tube 230 andincludes a pair of struts 234A and 234B that are separated by a pair oflongitudinally extending slits 235A and 235B. The catheter tube 230 mayalso include a tip member 238, an inner sleeve 240, and a protectivesheath (not shown), which is described above in the first embodiment.The guide wire 252 may extend through the entire device.

In the illustrated embodiment, however, the expandable portion 232includes a first pair of weakened regions 237A, 237B and a second pairof weakened regions 239A, 239B that are respectively located at oppositeends of the struts 234A and 234B. The illustrated weakened regions 237A,237B and 239A, 239B are formed by enlarged apertures that extend throughside walls of the expandable portion 232 that function as hinges. Theweakened regions 237A, 237B and 239A, 239B may help reduce the amount ofbending stress in the side walls of the expandable portion 232 when thestruts 234A and 234B are moved to an opened position. The struts 234Aand 234B may include any number or configuration of weakened regions.Further, it should be appreciated that any of the other embodiments inthis disclosure may also include weakened regions 237A, 237B and 239A,239B.

The illustrated struts 234A and 234B remain generally flat alongrespective lengths thereof in both a closed position (shown in FIG. 11)and an opened position (shown in FIGS. 12 and 13) so as to form an apex,although such a configuration is not required. The incising elements 236are provided along the generally flat portion of the respective struts234A and 234B. As such, the incising elements 236 may also function asstiffening members for increasing the strength of the struts 234A and234B. Further, this configuration can reduce the amount of stress in theconnection between the incising elements 236 and the struts 234A and234B, which may otherwise be caused by bowing of the struts 234A and234B.

As shown in FIG. 12, end portions of the incising elements 236 mayextend beyond the apex that is formed by each of the respective struts234A and 234B. This configuration can increase the effective height ofthe incising elements 236 when the expandable portion 232 is in theopened position. As such, the incising elements 236 may have a reducedheight when the expandable portion 232 is in the closed position, whichmay eliminate the need for the protective sheath (not shown).

The expandable portion 232 can be operated between the closed positionand the opened position by selective movement of the inner sleeve 240relative to the catheter tube 230, as described above in the firstembodiment. Alternatively (or in addition), the struts 234A and 234B canbe biased in the opened position. In such an embodiment, the protectivesheath (not shown) can be used to effect movement of the expandableportion 232 between the closed position and the opened position.

Referring now to FIGS. 14 through 16, there is illustrated a cathetertube 330 having an expandable portion 332, in accordance with a fourthembodiment of this invention. The catheter tube 330 and the expandableportion 332 may include any structural features as described andillustrated above in the previous embodiments, although such is notrequired. Similar features have been numbered with common referencenumerals but have been increased by 300 (i.e., 310, 320, 330, etc.). Itshould be appreciated that similar features are structured similarly,operate similarly, and/or have the same function unless otherwiseindicated by the drawings or this specification.

For example, the catheter tube 330 may extend from a handle assembly(not shown) as described above in the first embodiment. The expandableportion 332 is provided on a distal end of the catheter tube 330 and mayinclude a tip member 338. The catheter tube 330 may also include aninner sleeve 340 that is attached to the tip member 338 and a protectivesheath (not shown), which is also described above in the firstembodiment. The guide wire 352 may extend through the entire device.

In the illustrated embodiment, however, the expandable portion 332includes a pair of struts 334A and 334B that are supported thereon in acantilevered manner (i.e., not attached to one another or to the tipmember 338 at their distal ends), the purpose of which will be explainedbelow. The struts 334A and 334B are separated by a pair oflongitudinally extending slits 335A and 335B that extend from the end ofthe expandable portion 332. A pair of incising elements 336 isrespectively provided along outer surfaces of the struts 334A and 334B.It should be appreciated, however, that the expandable portion 332 mayhave any number or configuration of struts and incising elements asdesired.

As shown in FIGS. 15 and 16, the illustrated struts 334A and 334B aresupported on the expandable portion 332 so that they can be splayed openin a Y-shaped configuration. For example, the struts 334A and 334B canbe splayed open by drawing the inner sleeve 340 within the catheter tube330, as described above in the first embodiment. In doing so, the tipmember 338 slides along the inner surfaces of the struts 334A and 334Band pivots them outwardly. Alternatively (or in addition), the struts334A and 334B can be biased in the splayed open position. In such anembodiment, the protective sheath (not shown) can be used to effectmovement of the expandable portion 332 between a closed position and thesplayed open position.

The struts 334A and 334B remain generally flat along their respectivelengths in both a closed position (shown in FIG. 14) and the splayedopen position, although such is not required. As such, the incisingelements 336 may also function as stiffening members for increasing thestrength of the struts 334A and 334B. Further, this configuration canreduce the amount of stress in the connection between the incisingelements 336 and the struts 334A and 334B, which may otherwise be causedby bowing of the struts 334A and 334B.

As shown in FIG. 15, end portions of the incising elements 336 mayextend beyond the distal ends of the respective struts 334A and 334B.This configuration can increase the effective height of the incisingelements 336 when the expandable portion 332 is in the splayed openposition. As such, the incising elements 336 may have a reduced heightwhen the expandable portion 332 is in the closed position, which mayeliminate the need for the protective sheath (not shown).

The principle and mode of operation of this invention have beenexplained and illustrated in its preferred embodiments. However, it mustbe understood that this invention may be practiced otherwise than asspecifically explained and illustrated without departing from its spiritor scope.

What is claimed is:
 1. An intravascular catheter device for treatingatherosclerotic material located within a blood vessel, saidintravascular catheter device comprising: a catheter tube having acenterline; an expandable portion secured to a distal portion of saidcatheter tube and comprising a plurality of struts pivotably attached tothe expandable portion for movement between a closed position where thestruts extend parallel to the centerline and an opened position wherethe struts splay outwardly at an angle from the centerline of thecatheter tube; and a sharpened edge associated with at least one of theplurality of struts and configured to create an incision in theatherosclerotic material when the expandable portion is placed in theopened position and retracted axially through the blood vessel.
 2. Theintravascular catheter device of claim 1 further comprising: a tipmember supported for sliding movement along inner surfaces of each ofthe plurality of struts, wherein retraction of the tip member isconfigured to force each of the plurality of struts from the closedposition to the opened position.
 3. The intravascular catheter device ofclaim 2 further comprising: an inner sleeve disposed within the cathetertube and attached to the tip member wherein said inner sleeve issupported for sliding movement within the catheter tube.
 4. Theintravascular catheter device of claim 3 wherein: each of the pluralityof struts extend along an outer surface of the inner sleeve when theexpandable portion is in the closed position.
 5. The intravascularcatheter device of claim 3 wherein: each of the plurality of struts arerigid.
 6. The intravascular catheter device of claim 5 wherein: each ofthe plurality of struts are straight-line members.
 7. The intravascularcatheter device of claim 1 wherein: said sharpened edge extends parallelwith a longitudinal axis of the expandable portion when the expandableportion is in the closed position.
 8. The intravascular catheter deviceof claim 1 further comprising: an incising element extending from anouter surface of at least one of the plurality of struts, wherein thesharpened edge is located along an upper surface of the incisingelement.
 9. The intravascular catheter device of claim 8 wherein: theincising element extends along an entire length of the at least one ofthe plurality of struts, and the sharpened edge extends along an entirelength of the upper surface of the incising element.
 10. Theintravascular catheter device of claim 1 wherein: each of the pluralityof struts extend in a substantially linear fashion along substantiallyan entire length of the respective strut.
 11. The intravascular catheterdevice of claim 3 further comprising: a handle assembly secured to anend of the catheter tube; and a control member that is moveablysupported on the handle assembly and in communication with the innersleeve, wherein said control member is configured to selectively controlmovement of the expandable portion between the closed and the openedposition.
 12. The intravascular catheter device of claim 1 wherein: thestruts are biased in the opened position.
 13. The intravascular catheterdevice of claim 12 further comprising: a protective sheath supported forsliding movement along an outer surface of the catheter tube to controlmovement of the expandable portion between the closed and the openedposition.
 14. The intravascular catheter device of claim 1 wherein: thesharpened edge extends outwardly in a radial direction from an outersurface of the at least one of the plurality of struts.
 15. Anintravascular catheter device for treating atherosclerotic materiallocated within a blood vessel, said intravascular catheter devicecomprising: a handle assembly; a catheter tube having a proximal endassociated with said handle assembly; an expandable portion attached toa distal portion of said catheter tube and comprising a plurality ofstruts, wherein each of said plurality of struts has a first end whichis pivotally attached to the expandable portion for pivoting movementbetween a collapsed position where each of the plurality of strutsextend parallel to a centerline of the expandable portion and a splayedposition where each of the plurality of struts extend at an angle fromthe centerline; a tip member configured to pivot the struts between thecollapsed position and the splayed position when retracted or extendedalong the expandable portion; and incising elements extending along eachof the plurality of struts, wherein each of the incising elements has asharpened edge which is configured to create incisions in theatherosclerotic material when the expandable portion is placed in thesplayed position and retracted axially through the blood vessel.
 16. Theintravascular catheter device of claim 15 further comprising: an innersleeve connected to the tip member and supported for sliding movementwithin the catheter tube.
 17. intravascular catheter device of claim 16wherein: each of the plurality of struts extend in linear fashion alongan outer surface of the inner sleeve when the expandable portion is inthe collapsed position.
 18. A method for treating atheroscleroticmaterial located within a blood vessel, said method comprising the stepsof: providing an intravascular device comprising a catheter tube, anexpandable portion secured to said catheter tube and comprising aplurality of struts pivotally attached to the expandable portion formovement between a closed position where the struts extend parallel to acenterline of the expandable portion and an opened position where thestruts splay outwardly at an angle from the centerline, and a sharpenededge associated with at least one of the plurality of struts; locatingthe intravascular device within the blood vessel; placing the expandableportion in the opened position; and retracting the expandable portion tocreate incisions along the atherosclerotic material.
 19. The method ofclaim 18 wherein: the expandable portion is placed in the openedposition by movement of a control member located on a handle assembly;the control member is connected to an inner sleeve located within saidcatheter tube; the inner sleeve is attached to a tip member; andmovement of the control member is translated into movement of said tipmember by way of said inner sleeve.
 20. The method of claim 18 wherein:each of the plurality of struts are rigid members which extend in alinear fashion along an outer surface of the inner sleeve when theexpandable portion is in the collapsed position.